Additive friction stir deposition (AFSD) is a technology with several advantages for aerospace manufacturing. It is particularly valuable because it can deposit materials at low temperatures while retaining high quality and efficiency. This article introduces the operations of AFSD in detail and investigates its effect on three types of precipitation-reinforced aluminum alloys. Key challenges hindering the production of high-strength aluminum alloy components through AFSD are highlighted. AFSD utilizes solid-phase deposition to avoid problems like porosity and thermal cracking that can occur with other types of deposition, such as laser and arc depositions. However, the slow cooling of the deposited metal and the long residence time in the sensitive temperature range can cause issues. Subsequent layers exert a thermal effect on the previous layers during the AFSD process. This can lead to coarsening of the precipitates in the middle and lower regions, resulting in decreased strength in these areas. The top layer remains unaffected, but has poorer mechanical properties compared to the base material. To improve performance, aging treatment can be used to cause reprecipitation of some elements dissolved during AFSD, but it does not reach the values achieved by solid solution and aging (T6) treatment. T6 treatment after AFSD can renew uniformly distributed fine-strengthening precipitates, but it triggers abnormal grain growth (AGG) in the deposited material. Therefore, it is generally not recommended to subject solution treatment to metals deposited with AFSD. Further research should focus on alloy design, composite reinforcement and innovative techniques, which are essential to obtain high-strength precipitation-reinforced aluminum alloy components through AFSD.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |